Clover-leaf nucleus of atypical lymphocytes in CMV-mononucleosis syndrome: report of one case.

Atypical lymphocytes with clover leaf nucleus are a frequent finding in adult type T-cell leukemia, and are occasionally seen in an overnight blood sample. This type of cell has apparently never previously been reported in cytomegaloviral infection. The case of a thirty-seven-day-old female infant presented with cytomegalovirus induced mononucleosis syndrome; her blood smear revealed atypical lymphocytes with clover leaf nucleus.